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Lei H.-Y.,Peking University | Lei H.-Y.,Petrochina | Wang H.-Y.,Peking University | Wang H.-Y.,Petrochina | And 4 more authors.
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2012

Pyrolysis kinetics characteristics of oil shale samples obtained from Liushuhe basin were investigated by Rock Eval analysis. The pyrolysis characteristics were studied at different heating rates (10, 15, 20, 25, 30°C/min) from 200°C to 600°C. Based on the Friedman mathematical formula and Sestak reaction mechanism, the reaction activation energy and reaction function were obtained, and so the pyrolysis mathematical model was developed. This mathematical model can be used to calculate the hydrocarbon conversion and required times for the fixed conversion. It is found that the reaction activation energy is not a constant and is a variable with the variety of reaction temperature. The reason is that the pyrolysis reaction process of oil shale is complicated multistep reaction, in which reaction mechanism is variable in different temperature range.

Chen F.,Shanghai University | Di Q.,Shanghai University | Yuan P.,Shanghai Hailong Petroleum Tubular Goods Research Institute | Wang W.,Shanghai University | And 3 more authors.
Shiyou Xuebao/Acta Petrolei Sinica | Year: 2012

The difficulty in carrying cuttings is a universal problem encountered in drilling of highly deviated and extended reach directional wells or horizontal wells, and it significantly affects the safety and efficiency of drilling operation. We developed an effective hydroclean drill pipe (EHCDP) and studied flow behaviors of the annulus flow field with EHCDP by applying a realistic model technique of the computational fluid dynamics (CFD). Numerical simulation data were analyzed in terms of flow diagrams, velocity field, and pressure field, and the EHCDP mechanism was studied by examining the effect of a spiral groove structure on flow behaviors of the annulus fluid. The results show that fluid can form a vortex cavity near spiral grooves with EHCDP, which can effectively change flow behaviors of fluid in an eccentric annulus, resulting in the annulus fluid to move from the low-side of an annulus to the up-side of that, which will transport cuttings to the up-side of an annulus as well. In addition, the vortex near grooves will swirl cuttings into spiral grooves, then cuttings will be thrown into the up-side of an annulus with centrifugal force produced by rotation of a drill pipe, therefore, cuttings beds at the bottom hole can be effectively removed.

Gao Q.,Tsinghua University | Sun C.,Tsinghua University | Yang C.,China Petroleum Materials Corporation
International Journal of Human-Computer Interaction | Year: 2014

The potential of microblogging networks to spread information, ideas, and influence via social links has been recognized. Individuals at central or critical positions in the microblogging networks are expected to play an important role in spreading information, but this belief must be tested with empirical investigations in actual information dissemination. Furthermore, it is possible that individuals with different types of structural importance influence the information dissemination in different ways. This article examines the impact of five structural properties (degree, betweenness, closeness, tie strength, and k-value) on information dissemination capabilities by tracking the dissemination of 150 messages in Sina Weibo. The results highlight the importance of betweenness centrality, which best explains the influence on information dissemination distance and coverage size. It also best predicts the information dissemination efficiency. Degree centrality is found to be a strong predictor of one's influence among immediate followers. Tie strength negatively correlates with influence on the information dissemination distance and coverage size. These structural properties address different aspects of the information dissemination power and should be used in a complementary way when planning information dissemination strategies in microblogging systems. Copyright © Taylor & Francis Group, LLC.

Xing M.J.,Beijing Institute of Technology | Xue Q.,Beijing Institute of Technology | Suo S.F.,Tsinghua University | Liu C.Y.,China Petroleum Materials Corporation
Applied Mechanics and Materials | Year: 2014

Gas sealing performance of metal seal ring directly affects the security and reliability of equipment operation. Gas static seals of W-ring is taken as a study object, based on the theory of rough surface contact model and the theory of gas average flow model in the rough surface gap, the gas sealing leakage model is established to analyze the relationship between the leakage and the sealing load and surface roughness parameters. © (2014) Trans Tech Publications, Switzerland.

Li S.-B.,Shandong Computer Science Center | Li S.-B.,Beijing Jiaotong University | Lin Y.,Shandong Computer Science Center | Jiang Z.,Xihua University | And 2 more authors.
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2012

For eliminating the traffic jams and improving the operating efficiency of urban transport network, a predictive control strategy for traffic congestion was developed. The improved mesoscopic traffic simulation model was presented to simulate propagation of the urban traffic flow, using a method which was similar with stochastic dynamic traffic assignment to establish transportation network OD loaded model in order to acquire the traffic states in advance. Simulation results also validate the proposed method can control traffic jams.

Hu G.-D.,Lanpec Technologies Limited | Chu Y.-L.,China Petroleum Materials Corporation | Wang J.-B.,Lanpec Technologies Limited | Chang C.-M.,Lanpec Technologies Limited | And 2 more authors.
Petrochemical Equipment | Year: 2013

The corrugated sheet is core components of plate and shell type heat exchanger. Because of its work in severe environment of high temperature and high pressure and corrode etc. failure accidents happened from time to time. The finite element simulation technology was applied, through analysis it found that the thin corrugated sheet with higher efficiency heat exchanger of its low intensity is a problem which cannot be ignored. The results provide a new theoretical basis for plate and shell type heat exchanger design.

Zhao H.-J.,University of Electronic Science and Technology of China | Peng Y.,University of Electronic Science and Technology of China | Li J.,Beijing University of Chemical Technology | Zhu Z.,China Petroleum Materials Corporation
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2015

In the early stage of emergency incidents, rapidly and comprehensively assessing the emergency incident is conducive to timely and accurately grasp the trend of the events and meet the timeliness requirements of emergency response. To solve the complicated calculation process and the lack of calculation software as well as the low compatibility of the existing software, a rapid comprehensive assessment model was established based on two revised algorithms, the Simple Simos Process and PROMETHEE II. Two experimental emergency datasets are used to verify the SSPPM. The experimental results show that the SSPPM (Simple Simos' Procedure and PROMETHEE II Model) can quickly acquire weights of criteria and get the result of assessment timely. ©, 2015, Systems Engineering Society of China. All right reserved.

Xing J.-H.,Beijing Jiaotong University | Huang H.,China Petroleum Materials Corporation | Zhang J.-Y.,Sinopec | Yang Q.-S.,Beijing Jiaotong University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2015

Disc springs have been widely adopted in the isolation bearings of buildings and bridges. The damping and stiffness properties of the combination of disc springs influence the isolation effect significantly. However, there are obvious differences between the numerical simulation methods for the combination of disc springs with various boundary constraints and loading ways. Moreover, there is still lack of quantitative description of the damping characteristic of disc springs. B series disc springs with single disc, two foldings, three foldings, three foldings then reversed as well as six reversed groups of three foldings were taken into investigation respectively and both static and dynamic experiments were carried out. The influences of pre-compression quantity, dynamic excitation amplitude and loading frequency on equivalent damping and equivalent stiffness were discussed. Based on static experimental results, the reasonable coefficient of friction between disc springs was evaluated through the numerical simulation by using the software ANSYS considering the friction applied by the upper and bottom cover plates. The proposed coefficient was adopted in calculating the dynamic characteristics of the combination of disc springs subjected to dynamic loadings and the results accord well with experimental data. © 2015, Chinese Vibration Engineering Society. All right reserved.

Hu B.,China University of Petroleum - Beijing | Zhu H.,China University of Petroleum - Beijing | Ding K.,China Petroleum Materials Corporation | Zhang Y.,China University of Petroleum - Beijing | Yin B.,China University of Petroleum - Beijing
Applied Ocean Research | Year: 2016

The conjugate heat transfer of an underwater gate valve assembly is numerically investigated by 3D steady RANS CFD approach. Different schemes of turbulence models in combination with near-wall treatments including low Reynolds number modeling (LRNM) and wall functions (WF) are adopted in simulations. An underwater gate valve heat transfer experiment with the same scale of the computational model is conducted for validation. It is found that the realizable k-ε turbulence model in combination with LRNM is the most appropriate numerical scheme to solve the underwater conjugate heat transfer problem. Based on the simulation results, the flow and heat transfer characteristics of the underwater gate valve assembly are discussed. The temperature and convection heat transfer coefficient (CHTC) distribution are distinct on both windward and leeward surfaces affected by the flow field. The numerical approach is also promising for conjugate heat transfer calculation of similar subsea thermal-fluid system. © 2016 Elsevier Ltd.

Hu B.,China University of Petroleum - Beijing | Zhu H.,China University of Petroleum - Beijing | Ding K.,China Petroleum Materials Corporation | Xu F.,China University of Petroleum - Beijing | Zhang Y.,China University of Petroleum - Beijing
Journal of Mechanical Science and Technology | Year: 2015

This study focuses on the heat transfer characteristic of a horizontal subsea Xmas tree assembly at a high spatial resolution. Computational fluid dynamics (steady Reynolds-averaged Navier-Stokes) in combination with Low Reynolds number modelling (LRNM) is adopted for heat transfer analysis, which has been validated against a full scale underwater gate valve heat transfer experiment with good agreements. The characteristics of cold sea water flowing through the subsea tree, and of convection heat transfer between the subsea tree and ambient cold water are obtained. The typical “hot spots,” which have high Convection heat transfer coefficient (CHTC) and create great large amounts of heat loss, are numerically determined. Under the designed water depth, the effects of installation orientation, sea water velocity, and inner oil temperature on convection heat transfer are investigated as well. Such work is significant for thermal design of the subsea tree to increase structural reliability and flow assurance level. © 2015, The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.

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